基于模块化多电平换流器（modular multilevel converter，MMC）的柔性直流输电技术因其效率高、控制灵活、便于扩展至多端系统等优势，逐渐成为海上风电并网的重要方式。海上风电场送出的有功功率具有随机性和波动性，大范围的功率波动可能造成受端换流站功率越限、直流电压越限和交直流系统功率回环等问题。为此，提出了两种适用于大规模海上风电经柔直送出系统的受端功率协调控制策略。首先，介绍了送出系统基本结构和MMC控制策略。然后，设计了受端有功功率自均衡控制策略和共用外环的定直流电压控制，两种策略具有不同的技术特点，但均能够实现多个受端换流站之间的有功功率合理分配，从而避免不必要的功率越限、电压越限和功率回环等问题。最后，利用PSCAD/EMTDC仿真验证了两种控制策略的有效性。

Modular multilevel converter （MMC）-based DC transmission systems have gradually become an important way for integrating offshore wind power due to its advantages such as high efficiency, flexible control, and easy expansion to multi-terminal systems. The active power of offshore wind farms is random and fluctuating, and large-scale power fluctuations may cause problems at the receiving end converter stations, such as power limit violation, DC voltage limit violation, and power circulation between AC and DC systems. To solve these problems, two power coordination control strategies for the receiving-end of large-scale offshore wind power via flexible HVDC transmission systems are proposed. Firstly, the basic structure of the transmission system and the MMC control strategy are introduced. Then, the active power self-balancing control strategy at the receiving-end and the common-outer-control-loop-based DC voltage control strategy at the receiving-end are designed. These two strategies feature distinct technical characteristics, yet both enable rational active power distribution among multiple receiving-end converter stations, thereby preventing unnecessary power limit violations, voltage limit violations, and power circulation issues. Finally, the effectiveness of the two control strategies is verified by PSCAD/EMTDC simulation.